Analysis and manipulation of particles, such as proteins or other biological molecules, often requires introducing or injecting the particle into vacuum, where the particle must maintain its native conformation. Examples of particle manipulation or analysis that may require particle injection into vacuum include molecular structure determination, spectroscopy, particle deposition onto a substrate (to produce, for example, sensor arrays), nanoscale free-form fabrication, formation of novel low temperature forms of particle-containing complexes, bombardment of particles by laser light, x-ray radiation, neutrons, or other energetic beams; controlling or promoting directed, free-space chemical reactions, possibly with nanoscale spatial resolution; and separating, analyzing, or purifying these particles.
Therefore, for many technological and scientific applications, the ability to form a single-file beam of microscopic liquid droplets is of great interest. Thus, methods and apparatus for providing streams of particles that are adapted for injection of the particle into vacuum would be of great benefit to these various fields.